Quote: So it appears, my bad - time to update the BOM on the Cavalli DIY site, though the J511 is also listed as obsolete at Mouser. But it will work, if you can identify the part in Jeff's kit.   EDIT: See...

You should have both the rectifier diodes (4004) for the power supplies and the CRDs (5313) for the input stage CCS. They're tiny!

  First,   Many Shouts to Cee Tee for an impeccable job hosting! After more than a year's hiatus, it's great to see that the hobby/addiction is still thriving!  Loads of great gear and music,  rigs with a lot of thought and not just $$$ invested in them, and stellar folk made this the best...

  Quote: It was nice to see this at the Bay Area Meet, sorry i didn't get to listen...

I don't get out much anymore as my interests have shifted a bit, but I will be at this met to reconnect and see what's happening with the hobby. Not sure yet if I'll be bringing anything, but will update.   Thanks,   Bill

Quote: I get:   http://www.mouser.com:80/ProductDetail/NEC/EC2-12NJ/?qs=c5n%252bvICFHOauz9TRyhaK7A%3d%3d   10K in stock...   EDIT Seems to be 3K today       

If you're going to use RN55s, you might as well get 1/4 watt carbon films, there are plenty available that are about the same size as RN55s:   http://www.mouser.com:80/ProductDetail/KOA-Speer/CF1-4CT52R6R8J/?qs=sGAEpiMZZMu61qfTUdNhG1dhquwH4o0FfRLFhWtWO%252bc%3d   OR I have at least three...

Hopefully Alex will chime in - when I helped the original BoM, I asked this question, and I thought he said there is a reason these should be carbon for a reason. They're mighty wee little buggers...  

Quote: The Gigaworks? I plan to use one in my build, I have the case finished with the stepped attenuator mounted (but I haven't built my rev'd CTH yet).   Any further symptoms?      

So, Sachu, do you have some sets of 2238/968 to spare?   I have found Steinchen's old Jisbos chart (Note 2) interesting: http://www.diamondstar.de/jisbos/jisbos_partslist.html  I've loved my BJT build, even with the stock output devices.   Oh, and Horio - exceptional build!          

Quote:          

Speaking of headphone synergies and SIPs - I have always socketed the R18 resistors in my builds, allows you to swap in different values when you have your build up (but still pretty difficult to do when the amp's cased.) I don't want to be the nervous nellie - but BE CAREFUL when poking around...

I have built with socketed caps. Wasn't really worth the trouble, as most of the interesting caps will need some creative lead work to get in the amp comfortably, making the sips hard to use with the previous designs spacing. Might be different with the new lead spacing. Give it a try and let...

Great to hear! And my thanks as well for your participation!

Mullet,   All the input grounds get tied together. So, Left and Right input Ground can go to their respective (I might have labeled them IGL and IGR on the pot, but +G and IG in this diagram). Tie the pot ground pins together, then run a lead to IG on the PCB. DO NOT tie them to the output...

Inspirational, Horio. I just dug out my Balanced EHHA, sitting for over a year had caused it to lose a Q1/Q2 mirror pair! Fixed that and have been listening with JH-13pro balanced and Late Senn 600's SE. Truly a jewel... Looking forward to your project completion, I need to rewire and finish my...

Quote: Originally Posted by oneplustwo A bad trafo? How did you figure that out? What was the symptom? Heat, and smoke, eventually.

The 'just started working' a clue. Insidious bad solder joint C19 ->ground. And a bad Trafo. She's up and running now, letting her burn. Thanks Ti and all!

Not getting any voltage at R6/R7 - CR4 blown up? Q12: C: 0V B:-21.0 E:-21.x EDIT: Hmm, this is nuts, it worked for a minute. rechecking all my solder joints.

Q2, 5,6,9, 10, 12 test OK (tested 10 out of circuit). will check voltages again...

DOH! Intermediate DIY complacency: they were indeed the wrong devices. Replaced. Kids, inspect all your part numbers! Now I get +3 Volts on the neg rail. i suspect something else is amiss. Perhaps those .47Rs? EDIT: the .47s test fine. Will begin checking Q12 again, then 5,6,9,10

Quote: Originally Posted by amb Not necessarily. That varies from batch to batch. The current stock I have look identical between the N and P channel devices. The only way to be sure is to look at the markings. DOH! Hope I wasn't a dummy, and replaced them by memory. Will...

Hmm, I'll take those suggestions on the resistors, they ohm out pretty close to .47R in situ (not the best test, i know). From memory, the P channels have the shinier tab correct?

I recently fixed a σ22 I used to have in my EHHA (Bad Q1). I rigged it for 12V for another project, but it Looks like it somehow got toasted again on the bench (I had no negative output at all). I replaced the mosfets on the negative rail, and now I am getting the full rectified voltage (~21V)...

OK, Dr. C, I will stop hijacking the thread with discussions of other amps... and look forward to exploring other designs in their appropriate venues.